NOIP 考前 暴力练习

 1 #include <cstdio>
 2 const int Maxn=510;
 3 int n,m,a[Maxn],b[Maxn],cnt,Ans[Maxn],x;
 4 bool Check()
 5 {
 6     for (int i=1;i<=n;i++)
 7         if (a[i]>=2)
 8         {
 9             for (int j=1;j<=n+2;j++) b[j]=a[j];
10             b[i]-=2; bool flag=true;
11             for (int j=1;j<=n;j++)
12                 if (b[j])
13                 {
14                     if (b[j]<0) {flag=false; break;}
15                     int t=b[j]%3;
16                     b[j+1]-=t,b[j+2]-=t;
17                 }
18             if (!flag || b[n+1]<0 || b[n+2]<0) continue;
19             return true;
20         }
21     return false;
22 }
23   
24 int main()
25 {
26     scanf("%d%d",&n,&m);
27     for (int i=1;i<=3*m+1;i++) scanf("%d",&x),a[x]++;
28     for (int i=1;i<=n;i++)
29     {
30         a[i]++;
31         if (Check()) Ans[++cnt]=i;
32         a[i]--;
33     }
34     if (cnt==0) {puts("NO"); return 0;}
35     for (int i=1;i<cnt;i++) printf("%d ",Ans[i]); printf("%d\n",Ans[cnt]);
36     return 0;
37 }

 1 #include<cstdio>
 2 #include<set>
 3 #define LL long long
 4 using namespace std;
 5 const LL Mod=1000000000000000003;
 6 set<LL>S;
 7 LL KASE,Bin[105],a[105],Sum,mul=131ll;
 8 inline bool Dfs(LL k,bool two,LL Sta)
 9 {
10   if (S.find(Sta)!=S.end()) return 0;
11   S.insert(Sta);
12   while (!a[k]&&k<=100) k++;
13   if (k==101) return two;
14   if (a[k]&&a[k+1]&&a[k+2]&&k<=98)
15   {
16     a[k]--;a[k+1]--;a[k+2]--;
17     if (Dfs(k,two,(Sta-Bin[k]-Bin[k+1]-Bin[k+2]+3*Mod)%Mod)) return true;
18     a[k]++;a[k+1]++;a[k+2]++;
19   }
20   if (a[k]>=4)
21   {
22       a[k]-=4;
23       if (Dfs(k,two,(Sta-Bin[k]*4+4*Mod)%Mod)) return true;
24       a[k]+=4;
25   }
26   if (a[k]>=3)
27   {
28       a[k]-=3;
29       if (Dfs(k,two,(Sta-Bin[k]*3+3*Mod)%Mod)) return true;
30       a[k]+=3;
31   }
32   if (a[k]>=2&&!two)
33   {
34       a[k]-=2;
35       if (Dfs(k,1,(Sta-Bin[k]*2-Bin[100]+3*Mod)%Mod)) return true;
36       a[k]+=2;
37   }
38   return false;
39 }
40 int main()
41 {
42     Bin[1]=1; for (int i=2;i<=100;i++) Bin[i]=(Bin[i-1]*mul)%Mod;
43     scanf("%d",&KASE);
44     for (int Kase=1;Kase<=KASE;Kase++)
45     {
46         Sum=0;
47         for (int i=1;i<=100;i++) scanf("%lld",&a[i]),Sum=(Sum+Bin[i]*a[i])%Mod;
48         S.clear();
49         if (Dfs(1,0,Sum)) puts("Yes"); else puts("No");
50     }
51     return 0;
52 }